The present invention relates to a photoresist remover composition, and more particularly, to a photoresist remover composition for removing photoresist from a substrate during a photolithography process which is applied in manufacturing semiconductor devices and liquid crystal displays (LCDs).
Photolithography is a common process applied in manufacturing semiconductor devices, such as integrated circuits (ICs), large scale integrated circuits (LSIs), very large scale integrated circuits (VLSIs), and picture display devices, such as liquid crystal displays (LCDs) and plasma display panels (PDPs).
Briefly, in a photolithography process, a photoresist layer is deposited on a predetermined substrate, for example, a semiconductor substrate or a glass substrate. The substrate to which the photoresist is applied may be a bare substrate which has not undergone any process before the photolithography process. However, it is usual that the substrate exposed to the photolithography process has sub-structure such as metal interconnections, formed on the substrate through a series of previous steps. The photoresist layer may be formed over or on a portion of the substrate. However, it is more common to deposit a photoresist layer over the substrate. The photoresist layer can be deposited over the substrate by a variety of methods, and generally, by a spin coating method.
Next, an exposure mask having a predetermined pattern is arranged in contact with, or a predetermined distance above the photoresist layer. Then, the photoresist layer with the exposure mask is irradiated with a high-energy activating beam, such as ultraviolet (UV) rays, electron beams or X-rays. A portion of the photoresist layer formed over the substrate is exposed to a high-energy activating beam through the mask pattern, and a shielded portion is blocked from the high-energy activating beam by the mask pattern. After irradiation with a high-energy activating beam, the physical properties of the exposed portion change while those of the shielded region are maintained. The photoresist pattern immediately after irradiation, which has a latent pattern with physically changed and unchanged portions, is referred to as a xe2x80x9clatent imagexe2x80x9d.
The photoresist layer with the latent image is subjected to a developing process, to transfer the mask pattern onto the photoresist layer, which results in a photoresist pattern. Subsequently, the substrate underlying the photoresist pattern is etched using the photoresist pattern as an etching mask, to form a predetermined pattern in the substrate. Next, the unnecessary photoresist pattern is removed from the substrate, so that a series of photolithography processes are completed.
The present invention relates to the removal of photoresist from a substrate in a photolithography process, which is carried out after the formation of the photoresist pattern on the substrate is completed.
A conventional technique uses an aqueous inorganic acid solution or an aqueous inorganic base solution, as a photoresist remover. Japan Patent Laid-open Publication No. sho 64-42653 discloses a mixture of aromatic hydrocarbon and alkylbenzene sulfonic acid, as a photoresist remover. However, such existing photoresist removers corrode the lower metal interconnections and are harmful to the human body. For these reasons, use of an organic series solvent as a photoresist remover was taught in Japan Patent Laid-open Publication Nos. hei 4-124668, hei 4-350660, hei 5-273768, and hei 5-281753.
When the organic series solvent is selected as a remover, a substrate to be etched is dipped into the organic series solvent to strip photoresist from the substrate. This dipping technique needs a considerable amount of photoresist remover. Furthermore, an increasing need for a larger semiconductor wafer and a large-screen display, and a trend of mass production contribute to further increasing the amount of photoresist remover required. Such an increase in the amount of photoresist remover required is undesirable in terms of efficiency of the photoresist removal process, and is expensive.
Recently, a single-wafer treatment has been applied to remove photoresist from a large substrate. In a single-wafer treatment system, there are a plurality of tanks including photoresist remover reservoirs, and cleaning chambers containing photoresist remover or deionized water. During the photoresist removal process, in order to prevent the photoresist remover contained in a tank from being contaminated by the photoresist remover from any previously arranged tank, an air knife process is performed, which also extends the usable lifetime of a photoresist remover.
Photoresist residue is generated by drying or wet etching, ashing or ion implantation processes. However, a conventional photoresist remover cannot remove such photoresist residue. Thus, although the air knife process is performed, the remaining photoresist residue can be incorporated into subsequent tanks, thereby shortening the lifetime of the photoresist remover. As a result, the success of a subsequent process cannot be ensured, and a completed semiconductor device or a display may have operational defects.
The photoresist residue may be classified into particulate residue and spot-like residue. The pattern of the residues will be shown more clearly with reference to the appended drawings.
FIG. 1 is an optical microscope photo showing the surface of a substrate 10 after a metal line 15 is formed during a photolithography process, before photoresist is removed from the substrate 10. FIG. 2 is an optical microscope photo showing particulate residue 20 on the surface of the substrate 10 after the photoresist is removed with photoresist remover prepared in Comparative Example 1. FIG. 3 is an optical microscope photo showing spot-like residue 35 remaining on the surface of a substrate 25 during formation of metal lines 30a and 30b, which have different patterns from the metal line 15 of FIGS. 1 and 2. In particular, in the formation of miniature patterns, the presence of such small spot-like residue 35 may cause defects in a device, and thus it is desirable to prevent the occurrence of spot-like residue 35.
To solve the above problems, it is an objective of the present invention to provide a photoresist remover composition capable of completely dissolving and removing photoresist residue generated by dry or wet etching, ashing, or ion implantation processes, with good spreadability with respect to a variety of metal layers, and capable of removing particles falling from the photoresist residue, which are hardly removed even by air knife treatment.
The objective of the present invention is achieved by a photoresist remover composition comprising: 10 to 30% by weight amine compound; 20 to 60% by weight glycol series solvent; 20 to 60% by weight polar solvent; and 0.01 to 3% by weight perfluoroalkylethyleneoxide.
Preferably, the perfluoroalkylethyleneoxide is at least one selected from the group consisting materials having formula (1)
Rfxe2x80x94Axe2x80x94(CH2CH2O)nxe2x80x94Rxe2x80x83xe2x80x83(1)
where Rf is a perfluoroalkyl group of 1 to 14 carbon atoms; A is xe2x80x94(CH2)mxe2x80x94Oxe2x80x94, xe2x80x94(CH2)mxe2x80x94SO2NR1xe2x80x94, xe2x80x94(CH2)mxe2x80x94CONR2xe2x80x94, xe2x80x94SO3xe2x80x94, xe2x80x94CO2xe2x80x94 or xe2x80x94SO2N(R3)CH2CO2xe2x80x94; R is hydrogen or an acyl or alkyl group of 1 to 18 carbon atoms; m is an integer from 0 to 20, n is an integer from 0 to 5; R1, R2 and R3 are hydrogen, an alkyl group of 1 to 6 carbon atoms, or xe2x80x94(CH2CH20)xxe2x80x94R4, x is an integer from 1 to 20; and R4 is an alkyl group of 1 to 6 carbon atoms.
More preferably, in formula (1), A may be xe2x80x94(CH2)mxe2x80x94Oxe2x80x94; Rf is a perfluoroalkyl group of 1 to 14 carbon atoms; m is an integer from 0 to 20; n is an integer from 0 to 5.
Preferably, the amine compound is an aliphatic amine compound.
Preferably, the aliphatic amine compound is at least one of aliphatic primary amine compounds including monoethanol amine, 2-(2-aminoethoxy)ethanol and 2-(2-aminoethylamino)ethanol.
Preferably, the aliphatic amine compound is at least one of aliphatic secondary amine compounds including diethanol amine, iminobispropylamine and 2-methylaminoethanol.
Preferably, the aliphatic amine compound is at least one of aliphatic tertiary amine compounds including triethylaminoethanol.
Preferably, the glycol series solvent is at least one selected from the group consisting of ethyleneglycol methylether, ethyleneglycol ethylether, ethyleneglycol butylether, diethyleneglycol methylether, diethyleneglycol ethylether, diethyleneglycol butylether, propyleneglycol methylether, propyleneglycol ethylether, propyleneglycol butylether, dipropyleneglycol methylether, dipropyleneglycol ethylether and dipropyleneglycol butylether.
Preferably, the polar solvent is at least one selected from the group consisting of dimethylsulfoxide, N-methyl-2-pyrrolidone, N,Nxe2x80x2-dimethylacetamide, N,Nxe2x80x2-dimethylformamide and dimethylimidazolidinone.